I have looked all over and seen so much FUD on this - it is terribly confusing, and I thought that this forum is the place to ask as you people are so knowledgeable and helpful. I can't see why this is not a bigger subject given the use of Puppy Linux as a highly portable OS.

I have tried to find reliable info on how to measure speeds and how to improve file transfers, but the ideas I have encountered are too numerous to list here.

Hi,
See this few months old discussion. I still use f3 for testing my flash drive and usb ports. Same drive sometimes give slightly different result on different port.
Next week I am gonna add USB 3.0 PCI card to my machine. Then I will test more.

Yes, I saw that discussion when I did a lot of looking on the subject. I usually try to do a decent amount of research before asking a question here. This problem seems to elude significant progress, much less a resolution. The speeds of 6-7 megs/sec is not too far from my own values which I arrived at using the dd if=/dev/urandom of=/mnt/sdX/tempfile conv=fdatasync,notrunc given at the Arch Linux wiki on SSD benchmarking.

Riight now, I am gravitating more to looking at deficiencies with the kernel/driver. I fear such a thing can't be resolved. The other good avenue of inquiry involves filesystem type, partition alignment, block alignment, and transfer block size.

With the ATTO benchmarking program, I get around 15 megs/sec in WIndows using the same computer, flash drive, and filesystem.

Oh dear, I should have made it clear that I am looking for write speeds in particular. Naturally, I am more demanding and petulant when it comes to the harder of the two directions for data transfer...we don't do Linux because we're casual users I can live with 20-25 megs/sec for reads, but the 6 megs/sec for my flash drive writes is driving me crazy. The measurements I have given in the previous messages apply to write speeds.

I have had values similar to the above for the three flash drives I have checked in both Puppy and Lubuntu.

In the real world, write speed is faster than the 33.29 MB/s shown by f3write, and read speed is slower than the 197.30 MB/s shown by f3read.

I just copied a 1401 MB movie .avi from the (sata 6GB/sec) hard disk to the usb stick in 18 seconds. I issued the sync command in a terminal window as soon as the copy was finished and sync completed instantly. 1401 MB in 18 seconds = 77 MB/second, measured write speed.

I can't speak to the differences created by different OS or file systems (like, at all), so I'll leave that to others. But I do have something to contribute despite that.

There are major differences in speed between flash drives. I only became aware of this a few months ago, when I started looking for a flash drive to back up photos (as an alternative to more-expensive backup hard drives).

I could go into why, but, I want to admit that I don't fully understand the function of SSD memory controllers. That notwithstanding, what I learned is, there are a very few USB flash drives which incorporate something like a SSD memory controller and operate at speeds similar to a low end SSD. There are flash drives with a simpler controller and lower quality memory which operate a quick-but-slower speeds. And then there's the generic, price-before-all flash drives that provide no technical details beyond the Amazon price of $8.99. Yes they will take your data and disgorge it later, but not quickly and not with a long life expectancy.

No-name drives have their place, absolutely. I run Puppy off of many of them in fact! (Unless you care a ton about boot speed, it doesn't really matter ...) For transferring files here and there, who cares, right? But the 2GB freebie drive you got from a networking event isn't going to be good at absorbing a month's worth of photos at a time. You don't need to go overboard, but you do need to spend a bit more than the commodity-drive-prices to get a flash drive that won't drag. I got a Mushkin Ventura Plus. And if you DO care about speed, there are some options above that too . They're marketing 450MB/s for really high-end stuff, and last time I checked my admittedly low-end SSD can't hit that because Corsair swapped in substandard DRAM halfway through the production run (after the positive reviews were in from tech blogs!) and didn't change the part number ...

Ok I did the dd test on various drives and noticed I was getting 1.1 to 1.4MB/s on anything including tmpfs ! I tried a real file and voila speeds jumped to expected..I guess /dev/urandom is not a fast source in this case....

As for manufacturers/devices the sandisc 2GB one gave 2.5MB/s
both are fat32 format

For comparison the same test on tmpfs gave 54MB/s and IDE hard drive was 20MB/s ...this is a pentium 3 and a usb 2 card feeding a usb hub...so not a setup I expect to fly either but in this case the speed limit is still probably that of the usb device regardless. (and anything that may also limit speed in the kernel??)

And yes it appears kingston do the 'get the review then change the device but not the name' on their cheaper ssd boogie too.

I would have thought that would affect maximum possible speed...eg my tmpfs test giving 54MB/s which means its unlikely to affect a device showing only a few MB/s significantly. That 54MB/s would also be affected by the source file read speed...an IDE drive..indeed probably the main bottleneck. /dev/urandom was definitely a major slowdown for me.

Actually repeated the IDE to tmpfs and got ~70MB/s....after the first time...drive spin up/loaded to cache perhaps.
I also get pretty mush the same figure doing a tmpfs to tmpfs copy....

RAM and CPU are way ahead of the speed of physical and flash drives.... a newer system with faster multi core/ram and sata/usb3 would still have a similar speed ratio.

back to main topic... seem to have a method of determining true usb flash write speed on linux... need something comparable for windows since I have not tried that yet....

I had run some numbers on a laptop that I have running. There are conflicting numbers as, depending on which distro/OS I run, the numbers swing differently. Thus I cannot compute a confidence factor for the 3 USB devices just tested.

As such, we need an agreed to utility distro that is to be used to generate a set of values that aims to be a measurer of USB devices, HDD devices on bus-channels, where the distro remains constant and the devices are targeted to gather behavior. In some cases, specific scenarios need to be prescribed so that the results collected can have a degree of significance that applies to only the device behavior derived consistently to be a good valid measure.

Summary, something necessary for community agreement

We need a model to use as a test bed with a measurement utility for I/O storage devices. That model remains the same for all storage device results reporting.
Or

We need a measurement utility that can be used to measure distro I/O behavior keeping the storage device the same while interchanging distros.
Note: Recognize that these are measuring different things; namely the storage device(s), or, the system(s) I/O activity to a designated device.

Otherwise, the numbers as we are reporting are merely for a single specific case.

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